I find the interplay between Hispanic / Spanish speaking countries fascinating

As someone who is niether speaks spanish or knows anything about the spanish speaking cultures across latin and south america and spain I do find it really cool that so many countries can co-communicate with each.

Can someone tell me a little bit more about it. Can you tell from someone Spanish accents who is from columbia, who is from mexico, who is from spain and so on? What about appearence who is spanish who is bolivian?

Are all the south american and hispanic countries all friendly toward each other same way english speaking us, uk, aus, canada, nz are?